unable to create a file in SD card

Question

I am very new into the android development. In this project, I am trying to create a JSON objects and then want to write that JSON object into a file in SD card but I am getting the following exception: W/System.err: java.io.FileNotFoundException: /storage/emulated/0/avinash1.json: open failed: EACCES (Permission denied) Though I have even added the user-permission in the manifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.raviteja.youexample">

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />


<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

package com.example.raviteja.youexample;

import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;

public class MainActivity extends AppCompatActivity {


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    JSONObject obj = new JSONObject();

    try {
        obj.put("age", new Integer(100));
        obj.put("name", "Ravi");
    } catch (JSONException e) {
        e.printStackTrace();
    }

    JSONArray list1 = new JSONArray();
    JSONObject pnObj = new JSONObject();
    try {
        pnObj.put("num", "99009900");
        pnObj.put("type", "mhgchmc");
        list1.put(pnObj);
        obj.put("phoneNumber", list1);

    } catch (JSONException e) {
        e.printStackTrace();
    }

    File root = android.os.Environment.getExternalStorageDirectory();
    File dir = new File (root.getAbsolutePath());
    dir.mkdirs();
    File file = new File(dir, "avinash1.json");

    try {
        FileOutputStream f = new FileOutputStream(file);
        PrintWriter pw = new PrintWriter(f);
        pw.println(obj.toString());
        pw.flush();
        pw.close();
        f.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
     } catch (IOException e) {
        e.printStackTrace();
    }

}

}

Answer 1

You should maybe try to get the public directory with the command: getExternalStorage Public Directory(): android.os.Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS)

Although if you want to keep that info to yourself and not let any other apps touch it you should save it in your apps InteralStorage. Quick tutorial here: http://www.tutorialspoint.com/android/android_internal_storage.htm

Answer 2

Updating my Answer

use this method , it should work :

private void saveJson() {
    File root = new File(Environment.getExternalStorageDirectory().getAbsolutePath());
    if(!root.exists())
    {
        root.mkdirs();
    }
    File file = new File(root, "avinash1.json");
    try {
        if (file.exists()) {file.delete ();}
            FileWriter fw = new FileWriter(file);
            BufferedWriter bw = new BufferedWriter(fw);
            bw.write(json.toString());
            bw.close();

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

but be careful , whenever you call this , your file will be overwritten with new value , for escaping that , you should make unique name for your file , like including current date and time to your file name ...